Security systems are relied upon to secure environments and possessions such as cars, homes, businesses and prisons. Keys and locks are integral to most security systems but unfortunately, keys can be lost or duplicated and a security system can then be breached.
Electronic or electrically activated security assemblies often require a battery for their power source and this can be disadvantageous in that batteries require constant replacement and this increases maintenance costs.
To overcome the disadvantages of conventional lock and key systems as described above a conventional biometric security assembly has been developed that reads biometric data from an operator in order to verify the operator's identity.
A biometric security assembly which includes a biometric key and lock for engagement with the key is described in Australian Patent 757159. The biometric key is provided with a sensor as well as one or more electrical contacts that touch a mating contact(s) of the lock in use so that a signal representing a biocode of data in regard to the user of the biometric key is sent to processing means incorporated in the lock. Upon matching of the signal with an authorised biocode in a database associated with the processing means the lock may be opened to provide access to a facility.
While the abovementioned conventional biometric security assembly is satisfactory in use it is possible for this security assembly and other conventional security systems which utilise an electrical connection between the lock and the key to have problems in maintaining polarity of the electrical connection and with shorting of the electrical contacts to ground or each other while the key is being inserted in the lock. This problem has been addressed to some extent for example in U.S. Pat. No. 5,337,588 by allowing insertion of the key in only one orientation which limits its utility and through elaborate electromechanical means to ensure that the contacts do not short out, which increases the cost of manufacture.